Medical fluid machine with supply autoconnection

ABSTRACT

A system for automatically connecting tubing to a medical fluid machine includes at least one fluid container including a tube having a cap on an end of the tube, a shuttle configured to receive the tube, a driving mechanism configured to translate the shuttle, a cap removal device configured to remove the cap from the end of the tube, and a control unit programmed to cause (i) the driving mechanism to translate the shuttle holding the tube in a first direction towards the cap removal device so that the cap removal device can engage the tube cap, (ii) the driving mechanism to translate in a second direction away from the cap removal device so that the cap removal device removes the cap from the end of the tube, and (iii) the driving mechanism to translate the shuttle in the first direction with the cap removed from the tube so that the tube can be mated with the medical fluid machine.

PRIORITY CLAIM

This application claims priority to and the benefit as a continuationapplication of U.S. Pat. No. 8,945,042, filed Jan. 25, 2013, entitled“Medical Fluid Machine with Supply Autoconnection”, which is acontinuation of U.S. Pat. No. 8,361,009 filed Jun. 3, 2011, entitled“Medical Fluid Machine with Supply Autoconnection”, which is acontinuation of U.S. Pat. No. 7,955,295, filed Jul. 5, 2007, entitled,“Fluid Delivery System With Autoconnect Features”, the entire contentsof each of which are incorporated herein by reference and relied upon.

BACKGROUND

In general, the present disclosure relates to medical fluid deliverysystems that employ a disposable cassette. In particular, the presentdisclosure provides systems and methods for cassette-based dialysismedical fluid therapies, including but not limited to those usingperistaltic pumps and diaphragm pumps.

Due to various causes, a person's renal system can fail. Renal failureproduces several physiological derangements. The balance of water,minerals and the excretion of daily metabolic load is no longer possibleand toxic end products of nitrogen metabolism (urea, creatinine, uricacid, and others) can accumulate in blood and tissue. Kidney failure andreduced kidney function have been treated with dialysis. Dialysisremoves waste, toxins and excess water from the body that wouldotherwise have been removed by normal functioning kidneys. Dialysistreatment for replacement of kidney functions is critical to many peoplebecause the treatment is life saving.

Hemodialysis and peritoneal dialysis are two types of dialysis therapiesused commonly to treat loss of kidney function. Hemodialysis treatmentutilizes the patient's blood to remove waste, toxins and excess waterfrom the patient. The patient is connected to a hemodialysis machine andthe patient's blood is pumped through the machine. Catheters areinserted into the patient's veins and arteries so that blood can flow toand from the hemodialysis machine. The blood passes through a dialyzerof the machine, which removes waste, toxins and excess water from theblood. The cleaned blood is returned to the patient. A large amount ofdialysate, for example about 120 liters, is consumed to dialyze theblood during a single hemodialysis therapy. Hemodialysis treatment lastsseveral hours and is generally performed in a treatment center aboutthree or four times per week.

Peritoneal dialysis uses a dialysis solution, or “dialysate,” which isinfused into a patient's peritoneal cavity via a catheter. The dialysatecontacts the peritoneal membrane of the peritoneal cavity. Waste, toxinsand excess water pass from the patient's bloodstream, through theperitoneal membrane and into the dialysate due to diffusion and osmosis,i.e., an osmotic gradient occurs across the membrane. The spentdialysate is drained from the patient, removing waste, toxins and excesswater from the patient. This cycle is repeated.

There are various types of peritoneal dialysis therapies, includingcontinuous ambulatory peritoneal dialysis (“CAPD”), automated peritonealdialysis (“APD”), tidal flow APD and continuous flow peritoneal dialysis(“CFPD”). CAPD is a manual dialysis treatment. The patient manuallyconnects an implanted catheter to a drain, allowing spent dialysatefluid to drain from the peritoneal cavity. The patient then connects thecatheter to a bag of fresh dialysate, infusing fresh dialysate throughthe catheter and into the patient. The patient disconnects the catheterfrom the fresh dialysate bag and allows the dialysate to dwell withinthe peritoneal cavity, wherein the transfer of waste, toxins and excesswater takes place. After a dwell period, the patient repeats the manualdialysis procedure, for example, four times per day, each treatmentlasting about an hour. Manual peritoneal dialysis requires a significantamount of time and effort from the patient, leaving ample room forimprovement.

Automated peritoneal dialysis (“APD”) is similar to CAPD in that thedialysis treatment includes drain, fill, and dwell cycles. APD machines,however, perform the cycles automatically, typically while the patientsleeps. APD machines free patients from having to manually perform thetreatment cycles and from having to transport supplies during the day.APD machines connect fluidly to an implanted catheter, to a source orbag of fresh dialysate and to a fluid drain. APD machines pump freshdialysate from a dialysate source, through the catheter, into thepatient's peritoneal cavity, and allow the dialysate to dwell within thecavity, and allow the transfer of waste, toxins and excess water to takeplace. The source can be multiple sterile dialysate solution bags.

APD machines pump spent dialysate from the peritoneal cavity, though thecatheter, to the drain. As with the manual process, several drain, filland dwell cycles occur during APD. A “last fill” occurs at the end ofCAPD and APD, which remains in the peritoneal cavity of the patientuntil the next treatment. Both CAPD and APD are batch type systems thatsend spent dialysis fluid to a drain. Tidal flow systems are modifiedbatch systems. With tidal flow, instead of removing all of the fluidfrom the patient over a longer period of time, a portion of the fluid isremoved and replaced after smaller increments of time.

Continuous flow, or CFPD, systems clean or regenerate spent dialysateinstead of discarding it. The systems pump fluid into and out of thepatient, through a loop. Dialysate flows into the peritoneal cavitythrough one catheter lumen and out another catheter lumen. The fluidexiting the patient passes through a reconstitution device that removeswaste from the dialysate, e.g., via a urea removal column that employsurease to enzymatically convert urea into ammonia. The ammonia is thenremoved from the dialysate by adsorption prior to reintroduction of thedialysate into the peritoneal cavity. Additional sensors are employed tomonitor the removal of ammonia. CFPD systems are typically morecomplicated than batch systems.

Hemodialysis, APD (including tidal flow) and CFPD systems can employ apumping cassette. The pumping cassette typically includes a flexiblemembrane that is moved mechanically to push and pull dialysis fluid outof and into, respectively, the cassette. Certain known systems includeflexible sheeting on one side of the cassette, while others includesheeting on both sides of the cassette. Positive and/or negativepressure can be used to operate the pumping cassettes. Cassettes withother pumps or fluid transfer mechanisms may be used.

There are two concerns for patient using dialysis treatments, especiallyfor home-use peritoneal dialysis. Dialysis patients tend to be elderly,with many aged 50 or 60 years, and older. Connecting bags of dialysisfluid to a treatment machine may be difficult because of the forcerequired to push a connecting spike through a sealing membrane. Thisforce can be as much as 20 lbs or more, and may be required to connecteach of four bags every night. The force and physical dexterity requiredmake it difficult for significant numbers of patients to make theconnections properly, e.g., without spiking through a connecting line,rather than a sealing membrane. The difficulty encountered in makingconnections may lead to improper touching and contamination of one ormore of the lines, if the patient inadvertently grasps or touches aconnector or an portion which is sterile and is intended to remainsterile. Inadvertent touches can lead to infections and peritonitis, andmay require hospitalization or other stressful procedures.

Accordingly, what is needed is a better way to connect containers ofdialysis solutions to a dialysis machine, such as a peritoneal dialysismachine. The present disclosure addresses the above-described needs andconcerns.

SUMMARY

A first embodiment is a system for automatically connecting tubing whilemaintaining sterility. The system includes a frame for mounting adjacenta cassette in a dialysis machine, a shuttle mounted within the frame,the shuttle configured for receiving tubing from at least twocontainers, the tubing including a cap, a shuttle driving system fortranslating the shuttle within the frame, and at least two rotatingfingers configured for receiving and removing the caps, the fingersmounted to the frame and operably adjacent the shuttle. The system alsoincludes a finger rotating system configured for rotating the fingers ina plane parallel to a direction of travel of the shuttle, and a controlsystem for operating the system for automatically connecting tubing,wherein the system for automatically connecting tubing is configured forreceiving sterile tubing from at least two containers, the fingers areconfigured for receiving caps from the tubing, the shuttle is configuredfor advancing the ends of the tubing, the control system is configuredto rotate the fingers to remove the caps, and the cassette comprises atleast two spikes for piercing sterile sealing membranes of the tubingand making a sterile connection.

Another embodiment is a system for automatically connecting steriletubing. The system includes a frame for mounting adjacent a cassette ina dialysis machine, a shuttle mounted within the frame, the shuttleincluding a tubing side and a cassette side, the shuttle configured forreceiving tubing from a plurality of sterile containers of dialysisfluid, each container including a length of tubing and a cap, a shuttledriving system for translating the shuttle within the frame, and aplurality of rotating fingers, each rotating finger configured forreceiving and removing the cap from the length of tubing and configuredfor receiving and removing a cassette port cap, the rotating fingersmounted to the frame and adjacent the shuttle. The system also includesa finger rotating system including a shaft configured for rotating thefingers in a plane parallel to a direction of travel of the shuttle, anda control system for operating the system for automatically connectingtubing, wherein the system for automatically connecting tubing isconfigured for receiving tubing of a plurality of containers of dialysisfluid, the fingers configured for receiving caps from the tubing andcassette port caps, and the control system configured to translate theshuttle, to rotate the fingers, and to advance ends of the tubing intoan adjacent cassette, the cassette including at least two spikes forpiercing sealing membranes of the tubing and making a sterileconnection.

Another embodiment is a system for automatically connecting tubing. Thesystem includes a frame for mounting adjacent a dispensing machine, ashuttle mounted within the frame, the shuttle including a tubing sideand a dispensing side, the shuttle configured for receiving tubing froma plurality of containers, and a shuttle driving system for translatingthe shuttle within the frame. The system also includes a plurality ofrotating fingers, each rotating finger configured for receiving andremoving a tubing cap and also configured for receiving and removing adispensing machine port cap, the rotating fingers mounted to the frameand adjacent the shuttle, a finger rotating system including a shaftconfigured for rotating the fingers in a plane parallel to a directionof travel of the shuttle, and a control system for operating the systemfor automatically connecting tubing, wherein the system forautomatically connecting tubing is configured for receiving tubing of aplurality of containers of liquid, the fingers configured for receivingtubing caps and dispensing machine port caps, and the control system isconfigured to translate the shuttle, to rotate the fingers, and toadvance ends of the tubing into an adjacent dispensing machine, thedispensing machine including at least two spikes for piercing sealingmembranes of the tubing.

Another embodiment is a system for automatically connecting tubing. Thesystem includes a frame for mounting adjacent a dispensing machine, aplatform mounted within the frame, the platform including a tubing sideand a dispensing side, the platform configured for receiving tubing froma plurality of containers, and a plurality of moving mounts on theplatform, each mount further including a driving system for advancingand retracting the mount. The system also includes a plurality ofrotating fingers, each rotating finger configured for receiving andremoving a tubing cap and also configured for receiving and removing adispensing machine port cap, the rotating fingers mounted to the frameand adjacent the platform, a finger rotating system including a shaftconfigured for rotating the fingers in a plane parallel to a directionof travel of the mounts, and a control system for operating the systemfor automatically connecting tubing, wherein the system forautomatically connecting tubing is configured for receiving tubing froma plurality of containers of liquid, the fingers are configured forreceiving tubing caps and dispensing machine port caps, and the controlsystem is configured to translate the mounts individually, to rotate thefingers, and to advance ends of the tubing into an adjacent dispensingmachine, the dispensing machine including at least two spikes forpiercing sealing membranes of the tubing.

Another embodiment is a method for connecting dialysis bags to adialysis cassette. The method includes placing tubing from a dialysisbag into a shuttle of an autoconnect machine, the autoconnect machineincluding a frame, a shuttle and shuttle driving system mounted on theframe, a plurality of rotating fingers, each finger configured forreceiving a cap from dialysis bag tubing, and a finger rotating systemfor rotating the fingers, and wherein the tubing fits into tubing runsatop the shuttle, placing the tubing cap into a first pocket of one ofthe rotating fingers of the autoconnect machine, causing the rotatingfinger with the tubing cap to rotate in a direction away from theshuttle and toward a disposable cassette on an opposite side of therotating fingers. The method also includes steps of translating theshuttle a distance in a direction toward the disposable cassette,wherein translating the shuttle rotates or translates the rotatingfinger with the tubing cap, and causes only the rotating finger intowhich the tubing cap was placed to capture a port cap from a port of thedisposable cassette in a second pocket of the rotating finger,translating the shuttle in a direction away from the cassette, removingthe tubing cap from the dialysis bag and leaving the tubing cap in thefirst pocket, rotating the rotating fingers in a direction toward theshuttle, removing the port cap from the port of the dialysis cassetteand leaving the port cap in the second pocket, and translating theshuttle toward the dialysis cassette and causing a spike in the port ofthe disposable cassette to pierce a sealing membrane in the tubing, andtranslating the occluder to allow dialysis fluid to flow in the tubing.

Another embodiment is a method for connecting fluid containers. Themethod includes placing a connector from a fluid container into anautoconnect machine, placing a tubing cap from one of the fluidcontainers into a pocket of one of a plurality of fingers of theautoconnect machine, causing the finger to move or rotate in a directiontoward a dispensing machine on a different side of the fingers. Themethod also includes steps of translating the tubing and the tubing capa distance in a direction toward the dispensing machine, whereintranslating rotates the plurality of fingers, and causes only the fingerinto which the tubing cap was placed to capture a port cap from a portof the dispensing machine, translating the tubing in a direction awayfrom the dispensing machine, removing the tubing cap from the tubing andleaving the tubing cap from the tubing in the pocket, rotating thefingers away from the dispensing machine and in a direction to removethe port cap from the port of the dispensing machine, and translatingthe tubing toward the dispensing machine and causing a spike in the portof the dispensing machine to pierce a sealing membrane in the tubing.

As will be clear from the disclosure below, an autoconnect device may beused for both peritoneal dialysis and hemodialysis. In addition,embodiments of an autoconnect device may be used for dispensation oradministration of other fluids with devices other than dialysis orhemodialysis machines, such as for blood or blood-substitutetransfusions. Additional features and advantages of the presentdisclosure are described in, and will be apparent from, the followingDetailed Description of the Disclosure and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an exploded view of a first embodiment of an autoconnectmechanism used with a disposable cassette and a dialysis machine;

FIG. 2 is an isometric view of a second embodiment of an autoconnectmechanism for use with a dispensing machine;

FIGS. 3A and 3B are isometric views of alternate embodiments ofdisposable cassettes for use with an autoconnect mechanism and adialysis machine;

FIG. 4A is an exploded view of a container of dialysis fluid, tubing foruse with the container, and a cap for maintaining a sterile end of thetubing;

FIGS. 4B and 4C are alternate embodiments of a cap with an RFID chip orother direct part marking feature;

FIGS. 5A, 5B and 6 depict the occluder and the occluding mechanism;

FIG. 7 graphs experimental results for the force needed for connectingcontainers of fluid;

FIGS. 8A, 8B and 8C are a cross-sectional views of engagement between acontainers of fluid and spikes, such as those from a pumping cassette;

FIGS. 9 and 10 are rear and front perspective views of details of afirst embodiment of rotating fingers for use in an autoconnect machine;

FIG. 11 is an exploded view of the embodiment of FIGS. 9 and 10;

FIG. 12 is a side view of the embodiment of FIG. 9;

FIGS. 13-14 are additional views showing the functioning of the rotatingfingers;

FIGS. 15A, 15B, 16A, 16B, 17A and 17B depict operation of an autoconnectmachine;

FIG. 18 is a flowchart for a method of operating an autoconnect machine;

FIGS. 19-21 disclose alternative mechanical equipment for operating anautoconnect device;

FIGS. 22-23 are schematic diagrams for a control system for operating anautoconnect machine, a pumping cassette, and a dialysis machine; and

FIGS. 24-25 are flowcharts for methods of operating autoconnect devices.

DETAILED DESCRIPTION

The present disclosure relates to medical fluid delivery systems thatemploy a pump, such as a diaphragm pump or a peristaltic pump. Inparticular, the present disclosure provides systems, methods andapparatuses for cassette-based dialysis therapies including but notlimited to hemodialysis, hemofiltration, hemodiafiltration, any type ofcontinuous renal replacement therapy (“CRRT”), congestive heart failuretreatment, CAPD, APD (including tidal modalities) and CFPD. The cassetteis disposable and typically discarded after a single use or therapy,reducing risks associated with contamination. The autoconnect device isintended for reuse as a part of the dialysis machine.

Patient Care

An autoconnect device, as discussed below, is intended to ease theburden on dialysis patients, who may be elderly and in poor health, andthose who care for them, who may also be elderly, and who may also be inpoor health. The daily task of hooking up dialysis fluid bags is indeeddifficult for those with limited strength. In addition, it is easy toinadvertently break sterility or to contaminate the instrument or thecontainer of fluid. In general terms, and for which a detailedexplanation is given below, the autoconnect device works in thefollowing manner.

After the cassette is loaded into the dialysis machine, the userattaches tubing from one or more dialysis bags by laying tubing in thetop portion of the device and by placing caps from the tubing in thetops of special fingers on the top of the device. The autoconnectmachine is then activated. A series of pinchers or occluders grasps thetubing and a shuttle then moves the tubing forward with the shuttle. Theforward movement also causes the fingers to rotate forward, in thedirection of the shuttle motion and toward the dialysis disposablecassette. Only those fingers with a tubing cap will rotate sufficientlyto contact a shielding cap from a port of the dialysis disposablecassette. These fingers are rotated into the shielding cap or caps andgrasp the cap or caps. After this forward rotation, the shuttle reversesdirection, and the cap from the tubing, held in place by a restrainingorifice atop the finger, is removed by remaining stationary while theshuttle and the tubing moves backward. The finger is now rotated in theopposite direction, while grasping the cap from the disposable cassetteport, the rotation causing the cassette port cap to remain in the top ofthe rotating finger, thus removing the port cap. Both caps have now beenremoved without the user touching the caps.

The top of the finger (or fingers) now contains a cap from the tubingand a cap from the cassette port. The fingers are then rotated downward,causing the caps to fall from the tops of the fingers into a chute,drawer, or other area. The fingers remain in the downward position whiletherapy is in progress. Once the caps are disposed of, the shuttle againreverses direction. At this point, the caps have been removed and allthat remains before dialysis is to connect the end of the tubing, withits sterile seal, to the cassette port, which is also sterile. Theshuttle now translates forward pushing on the connector while the tubingis held in place by the occluder, and extends the tubing into a piercingneedle contained within the cassette port. The piercing needle ispreferably somewhat recessed from the outer lip of the port for ease ofmaintaining the sterile environment and a sterile connection. Once theneedle pierces the membrane seal of the dialysis tubing, the connectionis made and will remain secure. With the dialysis containers nowattached via a sterile connection, an after the occluder is released,dialysis may now begin. In the embodiments discussed below, theautoconnect device may be used to connect from one to five containers ofdialysis fluid. Other embodiments may be used to connect less than fiveor more than five containers. Still other embodiments may be used forone or more fluid containers other than dialysis fluid, such as blood,blood substitutes, saline solution, nutritional fluids, medications, andothers. For example, one of the containers may include a neutral fluid,such as saline, and a medication needed by the patient, such as heparin,insulin, or an antibiotic. These medication fluids may just as easily beused with the autoconnect device and a device for downstream infusion ordispensing.

The Autoconnect Device

Referring now to the drawings and in particular to FIG. 1, a dialysismachine 1 is intended for use with a disposable dialysis cassette 3 andan autoconnect machine 5. Autoconnect machine 5 in this embodimentincludes a frame or base 7, a central area 9 for disposal of caps fromthe dialysis cassette and from bags of dialysis fluid. In thisembodiment, frame 7 includes sides 12 a and back portions 12 b, joinedby hinges 12 c. Main chassis 10 includes a central area 11 includesdiscrete portions of channels 14 for tubing from the dialysis bags.Autoconnect 5 also includes top covers 13 on either side to shield andprotect the inner workings. Also included in top working area 19 is ashuttle 15 for advancing the tubing, an occluder 16, and fingers 17 forremoving caps from the dialysate bags and from the dialysis cassette.

In using the autoconnect device, a plurality of containers of dialysisfluid may be positioned in the vicinity of the dialysis machine or nearthe autoconnect device. Since dialysis bags typically include tubingabout 2 feet long, either position is possible and may be suitable. Ifthe dialysis machine includes one or more facilities for heating, thecontainers of dialysis fluid are desirable heated to a temperature closeto body temperature before use. Alternatively, the disposable dialysiscassette may include provisions for heating dialysis fluid as it isbeing pumped. For example, the dialysis cassette 30 depicted in FIG. 3Amay be used to warm the dialysis fluid.

The embodiment of FIG. 1 may be used as presented for automaticallyconnecting containers of dialysis fluid to the pumping cassette whilepreserving a sterile connection. Alternatively, the main chassis portionmay be used separately, as shown in FIG. 2, as an autoconnect device 20.Autoconnect 20 includes a frame 21, frame back wall 21 a, and alsoincludes a drive motor 22 and a drive system 23 for positioning shuttle24. Drive system 23 includes left and right lead screws 23 a, 23 b, anda power transmission system as shown, including a timing belt, and belttensioners as needed, to distribute power from motor 22 to the two leadscrews. The system could use gears rather than a timing belt. Drivesystem 23 includes at least mounts 23 c and bearings 23 d as shown, andalso preferably includes a drive train and any necessary gear reductionfor matching motor 22 to the desired speed for advancing and retractingshuttle 24. A brushed 24 VDC planetary gear motor, with a suitablecontroller, has been found satisfactory for the motor for thisapplication. Other suitable motors may be used.

Autoconnect 20 includes a central area 26 with discrete channels fortubing from dialysis containers, and also includes front occluder 25 aand a rear occluder 25 b for occluding or pinching tubing from thedialysis containers. In this embodiment, central area 26 includes fivechannels for placement of tubing from five dialysis containers.Occluders 25 a, 25 b each include openings for the tubing, in this casefive openings 25 c. In one embodiment, occluders 25 a, 25 b are bothpart of a single, U-shaped piece of sheet metal, in which occluder 25 aperforms the occlusion function, i.e., pinching the tubing so no flow ispossible, while occluder 25 b acts only to secure the membrane port intoshuttle 24. When the occluder is actuated and no flow is possible in thetubing, there will be no premature flow of fluid during spiking, and themachine may, with confidence, perform an integrity test. There are alsofive fingers 27 for grasping and removing caps from the ends of thedialysis tubing, and also for grasping and removing caps from the portsof a dialysis cassette used with the autoconnect and a dialysis machine.Visible also in FIG. 2 is a motor 28 for rotating fingers 27. A brushed24 VDC planetary gear motor, with a suitable controller, has also beenfound satisfactory for this application. Other suitable motors may beused.

Autoconnect device 20 preferably is enclosed in a housing 18, to protectthe device. The housing preferably also includes ducting 19 a connectedto a blower 19 b and HEPA or other filter 19 c. The filter providesclean air to the blower which can keep the housing under a slightpositive pressure during use, thus preventing dust, mold, and the likefrom entering the atmosphere of the device. This embodiment of anautoconnect device works in the following manner. A user furnishes oneor more containers of dialysis fluid and tubing for the containers, thetubing including a special cap for connecting via the autoconnectdevice. The tubing connects to the containers and the tubing is thenconnected to the dialysis machine via a disposable cassette. The specialcap is placed into the near side of the rotating finger and the tubingis laid into the channel atop the autoconnect device. The autoconnectdevice then begins its automatic sequence for connecting one or morecontainers of dialysis fluid to the dialysis machine.

The occluder translates to the left, thus grasping the tubing andholding it immobile within the shuttle. The shuttle translates forward,and each finger with a cap causes that finger to rotate forward, in thedirection of the shuttle movement. The movement of the finger causes thefinger to grasp the cap from a port on the disposable cassette. Theshuttle is now translated backward, away from the disposable. Thefinger, with the tubing cap atop, is captured by the port cap. When theshuttle translates backward, the tubing cap is removed because it isrestrained within the finger. After the shuttle translates backward, thefingers rotate in a backward direction. Since the cap or caps from thedisposable ports are captured by one or more fingers, this rotationremoves the cap or caps. Further rotation below horizontal causes thecaps to fall from the finger or fingers into a bin or open area belowthe fingers.

Movement of the shuttle, the occluder, and the fingers is controlled bya controller or microcontroller of the autoconnect device. As part ofthe controls, the shuttle is equipped with an optical sensor 24 a,mounted on the bottom portion of the shuttle. The optical sensor 24 a isguided by a stationary sensor track 21 b, mounted in parallel with thelead screws. Sensor track 21 b includes a series of notches as shown.The notches allow the optical sensor to keep the controller informed ofthe position of the shuttle. As will be obvious to those with skill inthe art, other sensors or techniques may be used, such as an encoder onshuttle motor 22, a proximity sensor mounted on the shuttle and targetsplaced at appropriate locations along the shuttle path, and so forth.For example, a hall effect sensor mounted on the shuttle may be used todetect its position by placement of magnets or other targets along theshuttle path. Alternatively, a position sensor for detecting a positionof the shuttle may be placed on the frame with notches, magnets, or thelike placed on the shuttle.

Fluid Containers and Disposable Cassettes

The autoconnect device is not limited to the embodiments above. Forinstance, other dialysis disposable cassettes may include the modeldepicted in FIG. 3A. Disposable cassette 30 includes a front portion 31,heating tube 32 and five ports 33 for connecting to dialysis fluidconnectors. Each port includes a cap 34 with a protruding, steppedcentral portion 34 a. This protruding portion makes it easier for theautoconnect rotating fingers (discussed below) to grasp the cap. Port 35a is used for input/output lines to and from the patient, and port 35 bis used for a drain. This particular model of a disposable cassette mayrequire an autoconnect device in which the tubing on the shuttle isoriented in a vertical direction, rather than in a horizontal direction.The shuttle will still translate back and forth toward and away from thecassette, and the occluders will translate in a direction perpendicularto the movement of the shuttle. The fingers will be oriented forrotation in a horizontal plane, rather than vertical. When the caps areremoved, they will fall away from and to the right of the autoconnectdevice. The ports have spikes, visible in FIG. 3B below.

The port caps 34 have symmetry, preferably radial symmetry. The caps arealso preferably radiation-sterilizable and steam-permeable, and are madefrom low density polyethylene (LDPE). LDPE is able to form a tight sealagainst the cassette port, protecting the sterility of the port. Otherrelatively soft materials may be used, but the stepped tips or nipplesshould be able insert themselves within the jaws of the rotatingfingers. Other embodiments may use non-stepped nipples or centralportions. The wider next portion of the nipple causes a slightinterference with the jaws, and allows the caps to be pulled off theports when the fingers rotate downward. Besides LDPE, other materialsmay be used, such as PVC, (poly-vinyl chloride), polyisoprene, siliconeand other suitable sterilizable materials.

FIG. 3B is an alternate embodiment of a cassette suitable for use withan autoconnect device. Cassette 30 a is similar to cassette 30, in thatit includes a front portion 31 a (shown), a back portion (not shown), aheating tube 32 a, and four ports 33 with spikes 33 a for containers. Inaddition, port 35 c is provided for connection to the patient, and port35 d for the drain, and port 35 e is used return from the patient. Theother ports also have spikes 33 a for making tubing connections. Ratherthan using the same port and line for to and from the patient, separatelines are used to help preserve the purity of the dialysate or otherfluid. For example, pediatric patients may use much smaller volumes ofdialysate, and much smaller volumes for recirculation. With very smallbabies, volume could be as low as 50 ml, while the spent dialysate inthe tubing to/from the patient and the cassette could be as much as 15ml. Separate lines to and from the patient avoid reuse of spentdialysate to the maximum extent possible.

A closer view of a typical dialysis fluid container is depicted in theexploded view of FIG. 4A. Dialysis bag 40 includes an outlet connection41 and is used with tubing 43 and a tubing connector 42 for connectingto dialysis bag 40. Tubing 43 includes a housing 46 for aradio-frequency identification (RFID) tag 47. RFID tag 47 is used toidentify this particular container and lot of dialysis fluid when thetubing is placed into the autoconnect device and the tag is read. Thetubing also includes a flanged handle 45 and a membrane port 45 a(internal to the tubing) or internal seal. Tubing 43 is terminated witha cap 44, the cap including a groove 44 a, a fold-down handle 44 b, anda core pin 44 c. Groove 44 a is preferably about 2.5 mm wide and about2.0 mm deep. The handle is useful for removing the cap manually if anautoconnect device is not available. The core pin 44 c is used forinterfacing and with the internal portions of tubing 43, to preserve thedimensional stability of the tubing up to internal membrane 45 a.

The tubing 43 and membrane port 45 a may be made from PVC, and the tubecap 44 is preferably a relatively soft material, both the tubing and thetube cap steam are preferably steam sterilizable and steam permeablematerials. Very soft silicone, with a Shore A durometer reading of about35 is preferred, although other materials, with a durometer from 50-100may also be used. Polyisoprene may be used, as may many styrenic blockcopolymers, such as those produced by Kraton Polymers, LLC, Houston,Tex., USA. Any of the softer, steam permeable grades will work well inthe application. In one embodiment, tube cap 44 may also serve as theRFID housing.

RFID housing 46 is easier to handle and install in the translatingshuttle if the housing is a little stiffer. For example, the housingsmay be made of HDPE, polycarbonate, harder PVC, or other material with ahigher Young's modulus. If housing 46 is more rigid, it is easier toinsert into the channels of the autoconnect shuttle. The RFID housingneed not take the shape disclosed herein, which is configured for easeof placement onto the shuttle. The housing may be any convenient anduseful shape that will reliably adhere to the tubing or even to the bagof fluid. In some embodiments, the RFID chip is placed into the housingin a secure manner, such as with a snap-fit. In other embodiments, theRFID chip is insert or over-molded into the housing. In the embodimentsdisclosed below, the RFID housing is configured for placement over thetubing, for ease of installation onto the shuttle. In other embodiments,the RFID housing may be placed or adhered onto the bag or container offluid, and is read by a single RFID reader on board the frame or theshuttle. The autoconnect system then directs the user to connect thetubing to a particular channel on the shuttle. Thus, the controllerknows the location of each connector and how to utilize each container.

In some embodiments, as shown in FIG. 4B, the RFID chip may be assembledor otherwise installed into the cap itself, without a separate housingfor the RFID chip. Using this technique, each rotating finger 27, asshown in FIG. 2, will include an RFID reader, to read the chip andreport back to the autoconnect controller. Thus, tubing cap 49 willinclude RFID chip 47 and will be read by an IR reader in the finger 27in which the cap is placed. In other embodiments, the cap of the tubing,or even the tubing itself, may include a mark as shown in FIG. 4C. Inversions using direct parts marking, appropriate information about thesolution to be administered, such as the solution, the lot number, andso forth, may be marked onto the cap or the tubing directly. Marks maybe made by imprinting, for example, by stamping or ink-jet or otherprinting method, as shown by imprinted mark 61 a. Marks may also be madeby placing a bar code indicia, 61 b, or by etching a mark 61 c. Etchingmay be accomplished by laser marking, for example. The marked cap ortubing may be detected by a camera 61 mounted on the autoconnect frameand operably connected to the autoconnect controller or the dialysismachine controller.

Placement and Identification of Tubing and Operation of the Occluders

The placement of tubing from the dialysis containers, or tubing fromother containers, is depicted in FIGS. 5A, 5B and 6. FIG. 5A depicts aview of shuttle 24 from the tubing side, while FIG. 6 depicts the viewfrom the opposite or disposable side. FIG. 5B shows a close-up of theoccluder drive mechanism. Autoconnect device central area 26 includesone or more channels 26 a for tubing. Each channel 26 a includes sidewalls 26 b with shroud 26 c, back end wall 26 d, front end wall 26 e,and an RFID reader 26 f. End walls 26 d, 26 e include rounded orificesto accommodate the tubing. In one embodiment, the channels 26 a and theRFID housing 46 are designed so that the RFID housing is retained in areleasable snap fit once it is inserted into the channel. The RFIDreader is intended to read the RFID tag 47 placed in each RFID housing46 as discussed above.

Occluder 25 a has been translated to the left in the direction of arrowA, capturing tubing 43 between occluder 25 a and shroud 26 c. Occluder25 a is translated using a 6 VDC gear motor 36 mounted on the shuttle,with a suitable speed reduction gearbox 37 and a lead screw 38 mountedto the occluder. Both occluders move at the same time. In someembodiments, spring 39 may used to bias the occluder to a closedposition. In other embodiments, the spring may be placed, for instanceon the opposite end of the occluder, to bias the occluder open. In yetother embodiments, the control circuitry may include a large capacitorto assure sufficient energy to drive the occluder to a safe closedposition as a fail-safe mechanism. At this point, the seals upstream ofthe tubing may not have been broken, and there may be no fluid in thetubing. The purpose of the occluder, or grasping mechanisms, is toocclude the tubing lumen and also to grasp the tubing to advance thetubing or, as will be seen, to retract the tubing and automaticallyremove the tubing cap. It will be understood that a solenoid or an aircylinder, or other mechanism, may be used to slide the occluder back andforth on its mounts or mounting pins rather than a lead screw.

Some embodiments may not use occluders. As discussed below, the tubingfrom the container fits tightly into a housing for an RFID chip. Withonly a small amount of friction, the tubing will adhere to the RFIDhousing and will follow along when the RFID housing is placed onto theshuttle. The tubing will also remain in place in the housing when theshuttle is advanced a short distance back and forth within the frame toremove the tubing cap and to pierce the tubing membrane. Someembodiments may thus not use occluders, but the tubing will still travelwith the shuttle, moving when the shuttle moves under the influence ofnormal friction between the housing and the tubing. It any event, theoccluder may be useful for other reasons, such as preventing loss offluid during spiking, or allowing the controller to conduct connectionintegrity tests. Failsafe closure, described above, may help preventcross-contamination in case of a power failure.

RFID chip housing 46 is sized to fit within channel 26 a, possibly witha snap fit. As seen from FIG. 6, from the opposite side of shuttle 24,back occluder 25 b has been translated to the right, in the direction ofarrow B to capture tubing 43. While arrows A and B seem opposite, thedirections are the same because FIG. 5A views the shuttle from thetubing side, while FIG. 6 views the shuttle from the disposable cassetteside. Each channel 26 a includes a front collar 26 g extending towardthe cassette. In addition to the collapsible handle 44 b on the tubingend 44, RFID housing 46 may also serve as a handle for placing tubing inthe channel. The RFID chip should be durable and rugged, and should beable to withstand sterilization, whether by gamma-ray irradiation, steamautoclaving, typically conducted at about 1 atm gage pressure at 121°C., or by chemical methods.

RFID tag 47 (not shown in FIG. 6) includes an antenna that may, or maynot, be coupled to an integrated circuit chip or chip that can store orcontain additional product information, tracking information, shippinginformation or any other desired product information. In operation, theprocessor, powered by the power source, provides a signal that istransmitted by the transceiver. The transmission energy of the signalcommunicated by the transceiver serves to inductively andcommunicatively couple the RFID tag 47 to the reader 26 f. Reader 26 fis essentially a small circuit board with circuitry for communicatingwith RFID tag 47. The circuitry usually includes its antenna, acontroller or control circuit, and input/output circuitry forcommunicating with the autoconnect controller. When the RFID readersends a signal, an electrical current is, in turn, inductively generatedwithin the RFID tag antenna. The electrical current can serve as a “zerobit” to simply indicate the presence or absence of the RFID tag 47.Alternatively, the electrical current can power the chip, therebyallowing the additional information stored thereon to be communicatedbetween the RFID tag 47 and the reader 26 f. In one embodiment, RFID tag47 records an indication each time the tag is read. In one embodiment,RFID tag 47 records and stores additional information from the systemcontroller, including at least one of a patient identifier, an amount ofdialysate or liquid administered, a date and time, and other helpfulmedical information.

The RFID tag 47 as illustrated is a passive tag, which includes nointernal power source and instead is inductively powered andinterrogated by the reader. In application with the present disclosure,RFID tag 47 can alternatively be a semi-passive device that includes abattery that is printed onto the substrate. The addition of the printedbattery power source allows the antenna to be optimized forcommunication, as opposed to current generation. In another embodiment,the RFID tag can be an active tag that includes a long-life battery, oneor more integrated circuits, display elements, storage elements, etc.

In some embodiments, the RFID tag 47 includes a transponder thatoperates at a relatively low frequency, about 125 kHz to about 134.2kHz, or from about 140 kHz to about 148.5 kHz, and having a read rangeof as low as about one inch. A high frequency transponder typicallyoperates at about 13.56 MHz with a read range of up to a meter. Further,transponders may even operate at an ultra-high frequency, such as 433MHz, or typically between about 868 MHz to about 928 MHz, with a readrange of about 3 m or beyond, such as those used for electronic tollcollection and the like. In the present application, small, lowfrequency RFID tags with very short range are preferred, so that eachtag is identified within its channel or range on the shuttle or otherpart of an autoconnect system. These ranges will preferably be less thanone inch, in the range of about 20-25 mm. The reading range depends onthe design of the reader or interrogator and can be kept short.

For purposes of the present disclosure, and regardless of physicalconfiguration, an RFID tag includes any device configured to communicateinformation via radio waves transmitted at frequencies of about 100 kHzor higher. In fact, the operating frequencies of individual tags can beconsidered a secondary consideration given that the overall structuresof typical tags are very similar. The RFID tags allow positiveidentification of each bag or container whose tag is placed into theshuttle. With this technique, the autoconnect controller, or thecontroller for the dialysis or other system, will know whether theplacement made is correct and incorrect and notify or alert the operatoror other personnel when an incorrect placement is made.

The above discussion focused on placing the containers of dialysatefluid, and their tubing and connectors, and automatically identifyingthe containers using RFID tags. It is clear from the above discussion,that other positive techniques may be used for identification, such asbar code labels or indicia on the tubing ends, and a bar code reader onthe autoconnect device. Still other techniques may be used, such asi-buttons from Maxim Integrated Products, Sunnyvale, CA. An i-button,similar to an RFID, is an integrated circuit with a uniqueidentification, contained in a small, flat, metallic package. Ani-button identification circuit usually requires touching to an i-buttonreader, but the principle of automatic and unique identification issimilar to that used with a bar code or an RFID tag. It will also beobvious to those with skill in the art that the autoconnect device maybe operated with no automatic identification feature, such as RFID tagsor barcodes. Identification of the fluid dispensed may be made manuallyor by entering a information, such as a code, manually into a computerfor tracking patient care.

Making Connections and Preserving Sterility

Once the tubing is in place, the tubing is connected so the fluid in thecontainers can be dispensed or otherwise distributed or used. FIG. 7illustrates graphically the problem in connecting bags of dialysissolution to the disposable cassette. The upper line with three pointsrepresents testing at different temperatures, while the lower linerepresents testing with an improved spike design. The force required forconnecting four bags at room temperature, 25 C, was about 140 lbs, orabout 35 lbs force for each connection, which connections are of coursemade by hand, one at a time. At cooler temperatures, 15 C, the force forall four was about 160 lbs, or about 40 lbs force each, while at 35 C,the force dropped to about 120 lbs, or about 30 lbs force each. Evenwith the improvement of a stepped spike, as discussed for FIG. 8A below,the force required is still about 80 lbs, or about 20 lbs force for eachconnection.

FIG. 8A depicts the improvement in the spikes discussed above and alsoillustrates a technique used to insure that the connection between thedisposable cassette and the tubing remains sterile. In this crosssectional view, tubing 43 with RFID housing 46 has been placed inposition and membrane seal 45 has been penetrated and broken by hollowspike 51 of the disposable cassette port 52. The outer diameter of thedistal portion 51 a of the spike is less than the outer diameter of thespike main portion 51 b, which may be slightly less than the diameter ofspike proximal portion 51 c. In addition, tubing end connection 48 mayinclude three stepped portions, distal portion 48 a with a larger innerdiameter, mid-portion 48 b with a smaller inner diameter, and proximalportion 48 c with a larger inner diameter, which provides clearance formaterial from the penetrated seal to fold or hinge out without occludingthe lumen and without requiring additional force to complete thepenetration.

Spike 51 is contained within port 52. Spike 51 includes an inner lumen53 so that when spike 52 penetrates membrane 45, a fluid connection isestablished between the dialysate solution bag tubing 43, and disposablecassette 5. The parts are designed so that the connection betweensterile parts is made before the membrane seal of the tubing is broken,thus preserving sterility of the connection. The spikes are preferable arelatively hard plastic, such as acrylic, polycarbonate, oracrylonitrile-butadiene-styrene (ABS). Cyclic-olefin containing polymers(COCs), especially those blended with ULDPE, may also be used for thecassettes and spikes. See, e.g., U.S. Pat. No. 7,011,872, assigned tothe assignee of the present patent, and which is hereby incorporated byreference.

The distal portion 51 a of spike 51 does not extend beyond the outer rimof port 52, i.e., the spike is shrouded within the port. In thisembodiment, port 52 extends a distance d₁ beyond spike 51 and spikedistal portion 51 a. This helps to prevent inadvertent touching andcontamination of the spike after the port cap is removed. When tubingend connection 48 is seated within port 52, the distal portion 51 a ofthe spike extends within tubing 43 for a distance d₂.

Spike distal portion 51 a, as shown, has a smaller outer diameter thanspike mid-portion 51 b. As noted above, tubing connection 48 innerportion 48 a has a larger inner diameter. When tubing 43 is connected toport 52, spike distal portion 51 a with a small outer diameterencounters connector portion 48 a with a larger inner diameter. In thisembodiment, and as seen in FIG. 8, the outer diameter of the spikeportion 51 a is less than the inner diameter of connector inner portion48 a, allowing the spike to pass through without interference. Uponfurther insertion, when connector inner portion 48 a encounters spikemid-portion 51 b, a seal is made between them just before the spike tippenetrates seal membrane 45. After penetration, spike mid-portion 51 bseals against tubing mid-portion 48 b. In addition, an outer seal ismade between tubing proximal portion 48 a and spike proximal portion 51c at the entrance to the tubing, i.e., the entrance to tubing portion 48a.

This arrangement of a stepped spike and stepped connector tubingminimizes insertion forces while simultaneously minimizing opportunitiesfor contamination of the connection parts. It will be recognized thatother spikes may be used, such as tapered, non-stepped spikes, as wellas tapered, non-stepped spikes with a leading edge on one portion of thespike arc. It will also be recognized that some spikes may have a sharpedge, while others will be blunt. Using a blunt edge helps to preventinjuries. In the present embodiment, designed for no contact with aperson using or operating the autoconnect system, sharp edges arepreferred, for minimizing the force necessary to make the tubingconnections.

FIGS. 8B and 8C depict an autoconnect mechanism in which the tubing tipsapproach the cassette 54 and spikes 55 a-55 d for sequential spiking. Inthis embodiment, shown with the tips of four containers of medicalfluid, the autoconnect mechanism has four independently-moving tips, 57a-57 d, from four containers with outlet tubing 56 a-56 d. Each tip hasa membrane or seal 58 a-58 d for spiking by the spikes 55 a-55 d. Thetubing and tips are mounted in independently-moving mounts 59 a-59 d ona stationary platform 60. As discussed below with respect to FIGS.19-21, separate movement for each mount may be provided by suitabledevices, such as solenoids, air cylinders, electric motors, or evenhydraulic cylinders. The mounts may be mounted on a shuttle or to trackson the autoconnect frame directly. In this embodiment, the shuttle doesnot translate, but instead each device provides the separateback-and-forth movement described for the shuttle.

FIG. 8B depicts the four tips 57 a-57 d and mounts 59 a-59 d approachingspikes 55 a-55 d in a sequential manner. In practice, one tip may beadvanced at a time. Preferably only one spiking connection is made at atime. As seen in FIG. 8C, the top two tips, 57 a, 57 b and membranes 58a, 58 b, have been spiked, one at a time, by spikes 55 a, 55 b. Thethird tip, 56 c, is approaching the third spike 55 c, and the fourthspike will be next. By using sequential spiking, the total forcerequired for penetration of the membrane by each spike is spread overfour time sequences, rather than all at once. Thus, the motor, cylinder,or solenoid that advances each mount may be smaller, since it needs onlyenough force to penetrate one seal, about 20-25 lbs force. Alignment ofthe mounts with the spikes may also be easier, since each mount, in itsown channel or pathway, need only align with a single spike. Even thoughthere may be a plurality of mounts and pathways to align, there are justas many to align in embodiments with a translating shuttle.

The above discussion focused on automatically making the connectionbetween containers of dialysate fluid and the inlet ports of adisposable cassette. By analogy, the same technique with suitablegeometries may be used for automatically making sterile connectionsbetween other containers of fluid and other dispensing or pumpingsystems. As previously noted, disposable cassettes may have theirconnection ports on the top of the cassette, or on the side. Of course,placement of the ports on the periphery of the pumping mechanism ispreferable, whether top, bottom, side, or on an edge of the top, bottom,or side. The same principles apply to other fluid container connections,such as bags of blood or blood substitute being connected to an inletport for a blood transfusion machine, such as a cardiopulmonary pump,bypass pump, or auto-transfusion machine. Still other applications arealso possible.

Operation of the Fingers and Removal of the Caps

An important part of making the connections is the automatic removal ofcaps from both the tubing and the ports of the cassette or other pumpingand dispensing mechanism. Automatic removal of the caps is an importantpart of the process because the caps, and the underlying ports andconnections, may easily be touched and thus contaminated if the caps areremoved by hand. Thus, as discussed above, special fingers are used toremove caps from both the product container tubing and from the ports ofthe pumping or dispensing machines, typically a disposable dialysiscassette.

One embodiment of cap removal fingers is disclosed in FIGS. 9-14. FIG. 9discloses a rear perspective view and FIG. 10 a front perspective view,of a finger 27 with left and right sides, 27 a, 27 b, a cap ejectorplate 27 c, finger 27 assembled with fasteners 27 d. Ejector plate 27 cis mounted within pocket 27 and travels via slot 27 e within left andright sides 27 a, 27 b. In one embodiment, as shown in FIG. 12, atorsional spring 27 j is mounted within finger 27 and under top surface27 f of the ejector to resist advancement of the ejector plate and toreturn it to the resting position shown in FIGS. 9-10. The top side offinger 27 includes a first pocket 73 with extended rails 71, the railsforming an orifice 72. Orifice 72 allows passage of tubing, as discussedabove, but is smaller than the diameter of the cap for the tubing. Thewalls of rails 71 are curved, together forming about 290 degrees of acircle, i.e., the periphery of the cap, or the portion of the cap insidethe outermost periphery, an inner periphery. This restraint allows therails to retain the caps when the shuttle and tubing are retracted, asdiscussed above. The orifice is preferably at least about 180 degrees,and experiments have found that 290 degrees works well for removingcaps. Other configurations with lesser coverage, such as severalangularly spaced points, are also adequate for stripping the tubing capfrom the tubing.

The top of finger 27 includes a second pocket 75, formed by extendedrails 74 of left and right sides 27 a, 27 b. In this embodiment, thepocket 75 is formed by the rails 74 and by inserts 74 a, spaced moreclosely than rails 74. The inserts are designed for grasping the centerportion of a cap from a dispensing or pumping machine, such as adialysis cassette. As noted above, fingers 27 grasp the stepped,protruding nipple from the dispensing or port cap. The interferenceshould be sufficient so that the cap is retained between the inserts. Inone embodiment, inserts 74 a are sharp near the center, so that when thefinger 27 is rotated and the shuttle translated into the nipple of theport or dispensing cap, the inserts cut into the nipple portion,grasping the nipple portion. When the finger begins to rotate inreverse, the cap remains captive and is pulled away from the port. Alsovisible from both the top and bottom of finger 27 is an ejector plate 27c contained within the finger. Finger 27 includes a through shaftway 76with a notched portion 77. A shaft rotates within the shaftway to rotatethe fingers and to advance and retract the ejector plate. When the capshave been removed as discussed above, and are resting in pockets 73, 75,the finger is rotated and the ejector plate is advanced to eject thecaps, all without touching and contaminating the tubing or the ports.

As seen in FIGS. 11-12, a shaft 81 actuated by motor 28 (see FIG. 1),input shaft 29 and gear train 80 extends through finger 27 and shaftway76. Also contained within each finger 27 inner space 79 is a leaf spring78, the leaf spring mounted against pin 82. Finger 27 can rotaterelative to shaft 81, its travel limited by pin 82. The leaf spring 78biases finger 27 to the back position, as shown in Fog. 12. There issufficient clearance within space 79 so that pin 82 and leaf spring 78can rotate back and forth, which limits travel, but also allows rotationof finger 27 in the general direction of the arrow C as shown, towardthe cassette. When the shuttle is advanced, finger 27 rotates as shownand as allowed by the pin. In one embodiment, this is about 5 degrees.This is sufficient to allow the inserts 74 a to grasp the port cap froma dialysis cassette port. Once rotation has taken place, the shuttleprevents reverse movement or rotation of finger 27. However, leaf spring78 is engaged by rotation of the finger, and now urges finger 27 torotate back, in the direction opposite arrow C. Thus, when the shuttleis reversed, and translates back, away from the cassette, finger 27 doesindeed rotate away from the cassette, while gripping the port cap insecond pocket 75 and removing it. The finger motor will cause the portcap to fall out as the finger is rotated down, out of the way. Asdiscussed above, the cap from the tubing is held in first pocket 73.

The caps have now been removed from the tubing and the port, and aredisposed of before making the connections between the tubing and theport. FIGS. 13-14 depict rotation of finger 27 about shaft 81. After theshuttle has been translated back, away from the fingers, the fingers maybe rotated downward to remove the caps. Output shaft 81 from gear train80 rotates the fingers to actuate the ejector plate 27 c and eject thecaps from pockets 73, 75. Gear train 80 may include bevel gears on theshafts to turn motive power from motor 28 and input shaft 29 ninetydegrees to rotate output shaft 81. In the alternative, a worm on theinput shaft and a worm gear on the output shaft, or crossed helicalgears will also work.

As finger 27 is rotated counterclockwise in the direction of arrow Dbeyond horizontal, ejector plate 27 c will encounter protrusion or camsurface 85 on back wall 21 a of the autoconnect frame. The interferencewill cause the bottom edge of ejector plate 27 c to bear against camsurface 85, advancing ejector plate 27 c through finger 27. As seen inFIG. 14, the top portions of the ejector plate, including a slidechannel 27 e top portion and top surface 27 f, and a top ejector rearportion 27 g, now protrude from the finger 27. Top surface 27 f willeject a cap from pocket 73 and top portion 27 h will eject a cap frompocket 75. The fingers will remain in the down position, out of the way,during therapy.

Overall Operation of an Autoconnect Device

The above description may be better understood by disclosing sequentialviews of the operation. FIGS. 15-17 lead this discussion, and FIG. 18provides a flow-chart version of the autoconnect process. In FIG. 15Aand FIG. 15B, tubing 43 has been placed in a shuttle 24 channel 26 a ofcentral area 26, along with RFID housing 46 and RFID tag 47. Forcomparison in FIG. 15A, an unoccupied channel 24 b, adjacent occupiedchannel 26 a is shown, along with the fingers corresponding to the usedand unused channels. Shuttle 24 has been advanced in the direction ofarrow E, causing slight rotation of finger 27, but only the fingercorresponding to channel 26 a. This slight movement can be seen by thefact that rails 71, 74 of finger 27 in channel 26 a have been advancedslightly.

As can be seen in FIG. 15B, this causes a slight clockwise rotation offinger 27 in the direction of arrow F and in the general direction offrame back wall 21 a. As noted, finger 27 rotates about shaft 81 withinshaftway 76. Returning to FIG. 15A, the slight rotation is sufficientfor second pocket 75 to capture port cap 34, the port cap to the portand corresponding to shuttle channel 26 a. This can be seen in top viewFIG. 15A, as the port cap 34 is captured between extended rails 74. Incontrast, in adjacent channel 24 b, extended rails 71, 74 have not beenadvanced in the direction of arrow A, and extended rails 74 are notadjacent port cap 34 in the adjacent channel 24 b.

In FIGS. 16A and 16B, shuttle 24 has retracted in the direction of arrowG, away from frame back wall 21 a. In channel 26 a, but not in channel24 b, tubing cap 44 has been removed from tubing tip 45, the tubing capretained in pocket 73 of finger 27. Finger 27 in channel 26 a remainsrotated rearward, as it was in the previous figures. Extended rails 71,74 in channel 24 b are thus offset from extended rails 71, 74 of finger27 in channel 26 a. Port cap 34 has been captured in pocket 75 of finger27, but only in channel 26 a, not in channel 24 b.

FIGS. 17A and 17B illustrate the next two sequences in automaticallyremoving the caps. Shaft 81 rotates counterclockwise in the direction ofarrow H, causing finger 27 to also rotate. As the rotation continues,ejector plate 27 c encounters a protrusion or cam surface 85 on backwall 21 a, causing ejector plate 27 c to advance within finger 27 in thedirection of arrow J, causing the ejector plate to push caps 34 a, 44out of pockets 73, 75 and ejecting them from finger 27. After the capsare removed, and after therapy is concluded, the fingers can be rotatedclockwise back to their normal position, opposite the direction of arrowH. In this embodiment, all the fingers are rotated, including fingerswith no caps. In other embodiments, gearing or other power is arrangedto engage only the fingers corresponding to channels with tubing.

The process as described above, for a method or process of automaticallyconnecting tubing, is easily visualized with the aid of the flow chartof FIG. 18. The first step 91 is to place the tubing into an autoconnectshuttle. A cap of the tubing is then placed 92 into a pocket of arotating finger. The tubing is grasped by closing 93 on the tubing witha holder or occluder. The shuttle is then translated 94 a short distanceforward, moving forward tubing and the cap, along with the shuttle. Thismovement is sufficient to cause a slight rotation only of a finger whichholds a tubing cap. When the finger is rotated, it captures 95 a portcap from a disposable cassette, or other dispenser, which will beconnected to the tubing.

The shuttle is now translated 96 in the opposite direction, away fromthe cassette, removing the tubing cap, which is held in a pocket of therotating finger. The finger is now rotated 97 away from the cassette,removing the port cap. The rotation may continue until the top of therotating finger is below horizontal, and causing the caps atop therotating finger to fall away. In one embodiment, the rotating fingerincludes an ejector plate that is actuated by a cam surface on the backwall of the autoconnect frame. After removal of the caps, the shuttle istranslated forward 98, piercing the tubing seal with spikes in thecassette port. It is understood that this process is applicable totubing from containers of a number of other liquid products, and may beused for automatically connecting to dispensers or pumping stations forthe products.

Alternative Mechanisms for Shuttle Translation

The above descriptions have used an electric motor and lead screws totranslate the shuttle, i.e., to move the shuttle back and forth in thedirection to and from the disposable cassette, or other pumping ordispensing mechanism. Many other techniques and equipment may be used, afew of which are described in FIGS. 19-21.

A ballscrew, with a rotating nut and traveling balls, may also be usedto translate the shuttle back and forth. FIG. 19 schematically depictsthe use of ball screws in shuttle transport system 110. The shuttletransport system includes an electric motor 111 and its controller,suitable power transmission elements 112, and a power divider 113, tosplit power from the motor and drive two ballscrews 114. Each ballscrewis driven by a suitable interface 115 from power divider 113. Eachballscrew may also include an encoder 116 for sensing the shaft orballscrew rotation, and thus the position of the shuttle 117. Theshuttle 117 is mounted to the rotating nuts 114 a of the ballscrews 117.As the ballscrews are rotated, the nuts translate or move back andforth, as does the shuttle. Other sensors may be used to determineshuttle position.

Pneumatic cylinders may also be used to move the shuttle back and forth,as shown in FIG. 20, depicting pneumatic shuttle transport system 120.Air may be supplied from a building compressor or plant air. For homeuse, however, a small air pump 121 and a suitable pressure regulator 122and controller may be used. In this embodiment, shuttle 127 is mountedon the traveling or rod portions 124 of air cylinders 123. The cylindersmay be single acting with an internal return spring 125 within thecylinder, or may be double-acting cylinders, for which no return springis necessary. Air cylinders 123 are mounted on mounts 126, mounted onthe autoconnect frame, for steady motion. The pneumatic driving systemalso includes a linear position sensor including linear transducers 128mounted to the shuttle and the frame and sending out signals to thesystem controller of the position of the shuttle. As seen in the lowerview of FIG. 20, the pneumatic system may include the pneumatic motivesystem as described, with shuttle 127 moved by air cylinder rods 124.Mounting rods or sliders 129 may also be used in parallel with the aircylinders.

Because of the relatively short distances involved in translating theshuttle, it is also appropriate to use solenoids, preferably electricactuated, to translate the shuttle. FIG. 21 depicts an application inwhich solenoids are used in a solenoid transport system 130. Of course,more than one solenoid may be used, but solenoids with more than oneposition change are now available, such as the multi-position modelsfrom Guardian Electric Mfg. Co., Woodstock, Ill., U.S.A. In thisapplication, shuttle 137 is mounted on the plungers 136 of solenoids132. The solenoids are powered and controlled by controller 131. Inaddition, the position of the shuttle is noted by at least one halleffect sensor 138 on the shuttle and magnets 135 mounted at appropriatelocations along the path of the shuttle. Other position sensors may alsobe used. In addition, the shuttle may use sliders 134, above or belowthe plane of the plungers, for travel in addition to the plungers of thesolenoids mentioned above for the pneumatic shuttle transport system.

In addition, other mechanical or fluid power devices may be used forshuttle transport, such as hydraulics. Hydraulics are typically not usedfor medical devices because of certain aspects of hydraulic fluid.However, the autoconnect device uses relatively low power, and non-toxichydraulic fluids are now available, such as the UCON™ FDC 300 and 400grades from Dow Chemical. These fluids are approved for incidental foodcontact and may be safely used. A hydraulic system for shuttle transportwould include at least a motor, a hydraulic pump, a reservoir for thehydraulic fluid, and control lines and systems for two-way movement ofthe shuttle.

The control systems for operating the autoconnect and the associatedequipment are also disclosed in FIGS. 22 and 23. The control system 140for the dialysis machine, the disposable cassette, and the autoconnectdevice are depicted in FIG. 22. The patient autoconnect controller 143is in communication with the disposable cassette controller 142 with anexternal interface. The autoconnect controller 143 is in communicationwith the dialysis machine controller 141 via an external patientautoconnect interface. Dialysis machine controller 141 includes amicrocontroller 141 a and a memory 141 b for storing a computer programfor operating the controller 141. The individual containers or bags ofdialysis solution 144 are supplied with unique identifiers and whenthese identifiers are read, the containers may be said to interface withthe dialysis machine controller 141, the disposable cassette controller142, or as noted above, the autoconnect controller 143. The systemcontrollers may also have other interfaces and connections. As notedabove, the unique identifiers may be read in many ways, for example, bya camera 145 operably connected to the dialysis machine controller.

The term camera as used here also includes related optical devicescapable of reading such a mark, including but not limited to, avisible/IR camera, a charge-coupled device (CCD), a CMOS image sensor orcamera, an optical sensor, or other suitable device. Cameras for imagingin visible light are readily available. Cameras that capture infrared(heat) images are also available. Recently, cameras that can producecomposite images using visible and infrared radiation are now available,such as those from Fluke Thermography and Fluke Corp., Everett,Washington, USA. Images that include an indication of temperature mayalso assist in the sense of letting users know when and if thecontainers have been warmed, for instance to body temperature. Thecamera may also be used to verify that the connectors are undamaged andthat they are correctly loaded into the shuttle or other portion of theautoconnect device. If the connectors are damaged or the markings areinconsistent with the expected markings for the containers, the machinecontroller for the dialysis system or for the autoconnect device maysignal an alarm or refuse to proceed. In one embodiment, the camera mayalso be used to inspect the color or other readily-determined opticalproperty of the contents of the containers, and if the inspection of thecolor or other property does not yield the expected result, the systemmay signal an alarm or refuse to proceed.

The autoconnect control system 150 is depicted in FIG. 23. Theautoconnect system is controlled by a microcontroller 151. A great manymicrocontrollers, and microprocessor controllers, are suitable for thisapplication. Indeed, even application specific integrated controllers(ASICs) may be used. We have found that microcontrollers fromSTMicroelectronics, Austin, Tex., work well. Other microcontrollers thatwill be satisfactory include those from Freescale Corp., Austin, Tex.,or Atmel Corp., San Jose, Calif. Other suitable microcontrollers mayalso be used.

System controller 151 is in communication with a great many otherdevices and parts of the autoconnect system, as discussed above. Systemcontroller 151 is in communication with RFID reader board 152, bar codereader board 153, if supplied, shuttle controller 154 a, shuttleposition sensor 154 b, finger controller 155 a, and finger positionsensors 155 b. In addition, the system controller 151 is incommunication and control with the occluder controller 156 a and theoccluder position sensors 156 b. In some systems, only a single occluderis used.

In addition, a number of additional sensors 157 are used in embodimentsof the autoconnect system. For example, temperature sensors may be usednear the tubing or the shuttle channels to detect a temperature relatedto the dialysis fluid or other liquid that is being auto-connected.Temperature sensors may also be used near the shuttle lead screws orother transport to insure that overheating is not occurring. Ifpneumatic cylinders or air solenoids are used, at least one or twopressure sensors should be used to keep a check on the health of theinlet air or air pump outlet that is used to supply air pressure. Ifhydraulic fluid is used, pressure sensors should be used to monitor andregulate hydraulic fluid pressure in the system.

It is also desirable to include a flow sensor 158. For example, anon-contacting optical flow sensor may be used to detect flow ofdialysis fluid within the tubing, based on minute changes in reflectionor refraction of the fluid within the tubing. A single pressure sensorof a two-port delta-p pressure sensor may be used along the tubing todetect flow by the change in pressure, or pressure drop, between theports. Actual rotating, contact-type flow sensors may also be used.Finally, it may also be prudent to add a fluid sensor 159 for measuringspecific properties of the solution, such as pH or conductivity. Thefluid sensor is preferably placed directly in the flow stream foraccurate measurement of the appropriate property.

FIGS. 24-25 are flowcharts depicting how the automatic identificationfeatures of the autoconnect device operate in different embodiments. Inone embodiment, depicted in FIG. 24, there is an RFID reader in eachchannel or position on the shuttle. There is also an RFID tag on thetubing from each container of fluid, such as dialysate fluid. The userplaces 160 an RFID tag with a unique identifier on tubing from the fluidcontainer that contains the fluid to be administered to a patient. Thetubing and RFID tag is then placed 161 into separate channels orpositions on the shuttle. The reader in each position then reads 162 theRFID tag on the tubing from one or more containers. If the computerrecognizes that the RFID tags corresponding to the containers are in theproper place, the operation continues 163. If one or more containers arenot in the proper position, an alert or alarm is issued 164 to the userbefore proceeding.

In another embodiment, depicted in FIG. 25, there is only a single RFIDreader or bar code reader operably connected to the autoconnect device.In this embodiment, the unique identifier for each container of fluidmay be located 165 on tubing or on the container or bag itself. Theuser, using the bar code reader or RFID reader, then reads 166 theunique identifiers on each container or tubing, the unique identifiersbeing an RFID chip or bar code indicia or label. The computer andcomputer program receives the information about the containers and theninstructs 167 the user concerning the position to place the tubing foreach of the containers. The user then places 168 the tubing from thecontainers into the instructed position on the shuttle in accordancewith the instructions. The user then operates 169 the autoconnect deviceand administers fluids to the patient.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose having skill in the art. For instance, the autoconnect machine maybe used with pumping cassettes used in peritoneal dialysis machines.Embodiments of autoconnect machines may also be used for cassettes forhemodialysis systems, automated peritoneal dialysis, and continuous flowperitoneal dialysis systems. These cassettes may employ any suitablepump or other fluid transfer mechanism, used with the autoconnectmachine. Such changes and modifications can be made without departingfrom the spirit and scope of the present disclosure and withoutdiminishing its intended advantages. Such changes and modifications areincluded in the appended claims.

What is claimed is:
 1. A system for automatically connecting tubing to amedical fluid machine, the system comprising: at least one fluidcontainer including a tube having a cap on an end of the tube; a shuttleconfigured to receive the tube; a driving mechanism configured totranslate the shuttle; a cap removal device configured to remove the capfrom the end of the tube; and a control unit programmed to cause (i) thedriving mechanism to translate the shuttle holding the tube in a firstdirection towards the cap removal device so that the cap removal devicecan engage the tube cap, (ii) the driving mechanism to translate in asecond direction away from the cap removal device so that the capremoval device removes the cap from the end of the tube, and (iii) thedriving mechanism to translate the shuttle in the first direction withthe cap removed from the tube so that the tube can be mated with themedical fluid machine.
 2. The system of claim 1, which includes anoccluder configured to occlude the tube while the driving mechanismtranslates the shuttle.
 3. The system of claim 2, wherein the controlunit is programmed to cause the occluder to occlude the tube before thecap removal device engages the tube cap.
 4. The system of claim 1,wherein the control unit causes a sealing membrane on the end of thetube to be spiked open when the tube is mated with the medical fluidmachine.
 5. The system of claim 1, wherein the medical fluid machineincludes a cassette, and wherein the tube is mated with the cassette atcontrol unit action (iii).
 6. The system of claim 1, wherein the capremoval device includes at least one finger configured to remove the capfrom the end of the tube.
 7. The system of claim 6, wherein the capremoval device is configured to rotate the at least one finger away froma path traveled by the shuttle after removing the cap from the end ofthe tube.
 8. The system of claim 1, wherein each at least one fluidcontainer includes a tube with a cap on its end, and wherein the controlunit is programmed to cause the shuttle to translate each of the tubessimultaneously.
 9. A system for automatically connecting tubing to amedical fluid machine, the system comprising: at least one fluidcontainer including a tube having a cap on an end of the tube; a shuttleconfigured to receive the tube; a driving mechanism configured totranslate the shuttle along a path; a finger rotating system configuredto engage the cap; and a control unit programmed to cause (i) the fingerrotating system to rotate while engaged with the cap so that the cap isremoved from the tube and the path of the shuttle, and (ii) the drivingmechanism to translate the shuttle in a direction towards the medicalfluid machine with the cap removed from the tube so that the tube can bemated with the medical fluid machine.
 10. The system of claim 9, whereinthe control unit is programmed to cause the driving mechanism totranslate the shuttle in a direction away from the medical fluid machineafter the finger rotating system has engaged the cap.
 11. The system ofclaim 9, which includes an occluder configured to occlude the tube whilethe driving mechanism translates the shuttle.
 12. The system of claim 9,wherein the control unit is programmed to cause the finger rotatingsystem to move out of a translation path of the shuttle.
 13. The systemof claim 9, wherein the control unit causes a sealing membrane on theend of the tube to be spiked open when the tube is mated with themedical fluid machine.
 14. The system of claim 9, wherein the medicalfluid machine includes a cassette, and wherein the tube is mated withthe cassette at control unit action (ii).
 15. A method for automaticallyconnecting tubing to a medical fluid machine, the method comprising:placing a tube of a medical fluid container into a shuttle; translatingthe shuttle in a first direction towards a cap removal device so that acap of the tube is engaged by the cap removal device; translating theshuttle in a second direction away from the cap removal device to removethe cap from the tube; and translating the shuttle in the firstdirection towards the medical fluid machine so that the tube is matedwith the medical fluid machine.
 16. The method of claim 15, whichincludes occluding the tubing before translating the shuttle towards thecap removal device.
 17. The method of claim 15, which includes movingthe cap removal device out of a translational path of the shuttle sothat the shuttle can be translated in the first direction to mate thetube with the medical fluid machine.
 18. The method of claim 17, whichincludes rotating the cap removal device out of the translational pathof the shuttle.
 19. The method of claim 15, which includes restrainingthe cap in a pocket of the cap removal device before translating theshuttle in the first direction towards the cap removal device.
 20. Themethod of claim 15, which includes reading an identification tag on thetubing to identify the contents of the medical fluid within thecontainer.